Adjustable cutting head and work support



March 15, 1955 E. H. FRAUENBERGER 2,704,011

ADJUSTABLE CUTTING HEAD AND WORK SUPPORT Filed July 10, 1.950

INVENTOR United States Patent ADJUSTABLE CUTTING HEAD AND WORK SUPPORT Ernest Harold Frauenberger, Brooklyn, N. Y.

Application July 10, 1950, Serial No. 172,921

4 Claims. (Cl. 90-41) This invention relates to metal working and the like, and more in particular to an arrangement for producing extremely fragile metal spindles with a high degree of accuracy.

Metal working is a highly developed art and yet there has been no thoroughly satisfactory arrangement provided for producing metal parts such as spindles of extremely small diameter. The known attempts toward this end have required extreme care in manipulation of the equipment and even with extreme care a work piece is often damaged or ruined after a great deal of expense and eifort has been expended. When producing articles of this type the work piece must be supported carefully and at the same time the tool must be controllable so that the size of the finished piece is within acceptable limits. Spindles or shafts of the order of seven thousandths of an inch in diameter are used for a variety of uses; for example, in scale models of machinery. It is an object of the present invention to provide for the production of such devices in an improved manner. It is a further object to provide apparatus for carrying out the above which is inexpensive to manufacture, sturdy in construction, and which may be operated and controlled even by relatively unskilled perators. 'It is a further object to provide apparatus of the above character which is adaptable to many conditions of use and which may be built of a size and character to produce articles of such size and quality as is desired. These and other objects will be in part obvious and in part pointed out below.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and in the several steps and relation and order of each of the same to one or more of the others, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the drawings:

Figure 1 is a perspective view of a tool constituting one embodiment of the invention together with a work piece withdrawn from the tool;

Figure 2 is a greatly enlarged longitudinal sectional view on the line 22 of Figure 1;

Figure 3 is an end elevation of the tool;

Figure 4 is a perspective view of the cutting and guide portion of the tool of Figures 1 to 3;

Figure 5 is a perspective view of another embodiment of the invention; and,

Figure 6 is a side elevation of another embodiment of the invention.

Referring particularly to Figure 1 of the drawing, a tool 2 has a hollow spindle 4 which carries a shell head 6 rigidly fixed thereto. Shell head 6 is hollow and has a threaded portion 8 at its left-hand end. Threaded onto portion 8 is a sleeve 10 (see Figure 2) which has at the left a somewhat frusto-conical nose 12 and at the right a knurled portion 14. The nose portion has a tapered inner surface 13 of minimum diameter at the extreme left. As indicated above, the shell head 6 is hollow and it has a central bore 16 in which is snugly received an elongated somewhat cylindrical cutter and guide member 18 shown best in Figure 4. Member 18 has a main cylindrical body and it is provided with four equally spaced longitudinal slots 20 which extend from the left-hand end of the member to adjacent the righthand end and thus form four arms 22 each of which is attached at its right-hand end to the unslotted cyhn- 2,704,011 Patented Mar. 15, 1955 "Ice drical end portion 24. Member 18 has at its left-hand end a cutting and guide end head 26 formed by segiznzental end portions 28, respectively, of the four arms The end head is provided with a tapered frustoconical surface 30 which mates (see Figure 2) with the inner surface 13 of nose 12. At the right, the end head 26 is of greater diameter than the bore 16 in shell head 6 so that a shoulder 32 is provided on portion 26 which rests against the end of the head so as to hold member 18 from moving to the right from the position shown. Thus, when sleeve 10 is turned onto portion 8 of the shell head, surface 13 engages the surface 30 of end head and tends to urge these portions together. Member 18 is of tempered steel and the portions 28 are normally held resiliently so that they are spaced from each other by the slots 20, but the turning of sleeve 10 is effective to move these portions progressively together against the spring action of arms 22.

The left-hand face of each of the portions 28 is ground to form a somewhat tangential and generally radial cutting edge 34 which is the leading edge when the tool is rotated (counterclockwise, Figure 3). These cutting edges extend tangentially from an imaginary circle or cylindrical surface indicated in broken lines at 36 and bounded by the four adjacent longitudinal edges 38 of the portions 28. As will be explained more fully below, during use a piece of stock is pushed axially toward the tool and these somewhat slightly ofiset radial cutting edges 34 cut away its end face and reduce it to a cylinder or spindle of the size of the circle 36. As an example, the stock may be a brass bar or rod of any diameter less than the diameter of the outer ends of the cutting edges 34. The diameter of the circle 36 and, therefore, the diameter of the finished work piece may be changed by turning sleeve 10 so that the end portions 28 are moved together or farther apart as desired. This adjustment is then maintained by a lock nut 39 which is on the threaded portion of the shell head 6 at the right of sleeve 10 and is tightened against the shell. The outer surface of nut 39 is knurled to permit easy manual turning.

Assume that the tool is rotating as indicated by the arrow (Figure 1), a work piece 40 in the form of a brass bar is moved from the left toward the tool along the axis of rotation; when the stock encounters the tool, the cutting edges 34 cut away the stock except at the central portion circumscribed by the circle 36 (Figure 3). This central cylindrical portion of the stock is not cut away and as indicated in Figure 1 forms a spindle 42 and this spindle 42 passes into the space between the portions 28 of the tool. Within this space this spindle 42 is supported by the longitudinal edges 38 so that a fixed pivotal relationship is provided between the tool and the stock. Furthermore, the spindle is held from bending by its engagement with the edges 38. As the work proceeds this spindle extends to the right (see Figure 2) and may even project through the bore of the supporting spindle 4.

Referring to the left-hand portion of Figure 2, the movement of the portions 28 together causes the lefthand ends of edges 38 to be adjacent each other and at the right they gradually extend apart slightly. The contact with the spindle 42 is sufiicient for the edges 38 to provide the support referred to above, but these edges also frictionally engage and somewhat polish the surface of this spindle. Therefore, the tool not only cuts away the metal and supports the stock and the work piece, but it also effects a polishing and finishing action.

In this embodiment, air under pressure is supplied to the right-hand end of the supporting spindle 4, and the air is discharged through slots 20 to the right and thence radially outwardly so that it blows over the work piece and outwardly along the working surfaces. This carries away the metal shavings and it also cools the tool and the working piece. Under some circumstances the work piece may be rotated and the tool held stationary along the axis of the rotation.

It may be desirable to sharpen the end of the stock prior to the first engagement with the tool so as to form a point on the stock which projects along the axis of rotation and enters the circle 36. This gives an initial pivot which supports the work piece and insures that the work piece and the tool will remain in proper relationship. In this embodiment four cutting segments are provided and each has a single cutting edge. It has been found that this is an ideal arrangement for certain types of work, although for other types of work a greater or lesser number of cutting edges or segments may be provided. In this embodiment the cutter and guide member 18 is driven by the frictional engagement at its shoulder 32 and by the frictional engagement between surfaces 13 and 30. This has been found to be satisfactory for the operations discussed above, although it is understood that a more positive driving engagement may be provided between the elements.

In the embodiment of Figure a shell head 46 has three cutting segments 48 which project from an opening on the left-hand end of the cutting head and each of which has a radial cutting edge 50. These cutting segments 48 are adjusted by an adjusting sleeve 52 which has teeth 54 along its left-hand edge and there are pivot holes 56 in the adjacent surface of head 46 which receive an adjusting wrench or spindle, thus to turn sleeve 52. The sleeve may be so tightly fitted that its turns with considerable friction and, therefore, tends to hold any adjusted position.

The opening in head 46 through which the cutting segments project is not circular but rather somewhat "scalloped so that it is bounded by three arcs, each of substantially one-hundred and eighty degrees. The

cutting segments 48 are similarly shaped so that each of them in effect projects through an arcuate slot or recess portion. The cutting segments are held apart and retained in these recess portions so that there is a radial driving relationship between head 46 and each of the cutting segments. The mechanism for adjusting the cutting heads 48 is not shown in the drawings but it involves internal slots in the head and an internal helical groove in sleeve 52. Each of the cutting segments is snugly fitted in one of the slots and has a radial end portion which projects into the spiral groove. This is a mechanical movement which can be well understood without a further showing.

In the embodiment of Figure 6 the arrangement is similar to that of Figures 1 to 4 but it includes a micrometer adjustment which indicates to the operator the exact size of the work piece which will be produced. Accordingly, the embodiment of Figure 6 includes a rotatable head 60 having an adjusting sleeve 62 threaded on its left-hand end and adapted to adjust four cutting segments 64 which are similar to those of the embodiment of Figures 1 to 4. Sleeve 62 has an integral micrometer sleeve 66 at its left-hand end which turns with sleeve 62 and overhangs a micrometer shell 68 which is press-fitted onto head 60. The micrometer shell bears indicia at 70 and sleeve 66 bears indicia at 72, and the arrangement is such that a micrometer reading is made on these two indiciae which indicates the exact size of the free opening between the cutting segments 64. Minute adjustment of shell 68 may be made by inserting a spanner wrench 74 in a pair of holes in the shell. Air is passed to the bore of head 60 by connecting a pipe to the radial hole 76.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawing, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. An adjustable cutting head assembly for cutting relatively small diameter spindles from pieces of stock material with a high degree of accuracy comprising a support member, a hollow shell secured to said support member and having a central bore, a cutting and guide head having a rear portion within the bore of said hollow shell and a front portion projecting at least partially therefrom, said front portion including a plurality of segmental end portions, each segmental end portion having an offset radial cutting edge extending across the front face of said cutting and guide head, each ofsaid segmental end portions including a pair of longitudinal surfaces meeting at a longitudinal guiding and polishing apex edge extending approximately parallel with the axis of the bore of said hollow shell, each of said apex edges facing forward at the axis of said bore, whereby to secure a uniform polishing action upon the spindles of work pieces extending along the axis of said bore, and adjustable clamping means surrounding said cutting and guide head for moving all of said segmental end portions closer together whereby each of said longitudinal guiding and polishing apex edges is moved closer to the axis of said bore, whereby to guide and polish smaller diameter spindles.

2. An adjustable cutting head assembly as claimed in claim 1 and wherein said support member has a passageway therein communicating with the bore of said shell, whereby air can be passed through said head assembly past said longitudinal guiding and polishing apex edges to said ofiset radial cutting edges.

3. An adjustable cutting head assembly as claimed in claim 1 and wherein said support member has a passageway therein connecting with the bore of said shell, the axis of said bore being aligned with said passageway, whereby said passageway provides clearance to receive the spindles of long work pieces.

4. An adjustable cutting head assembly as claimed in claim 1 and wherein said clamping means is a rotatable sleeve having an internal tapered clamping surface and internal screw threads, said hollow shell having external threads engaging said internal threads, whereby said sleeve is screwed longitudinally of said shell to afiect radial adjustment of the longitudinal guiding and polishing apex edges of said segmental end portions, and micrometer indicating indicia on said sleeve and on the outside of said shell, whereby the radial adjustment of said longitudinal guiding and polishing apex edges can be readily determined.

References Cited in the file of this patent UNITED STATES PATENTS 1,155,211 Carpenter Sept. 28, 1915 1,424,392 Baker et a1. Aug. 1, 1922 1,623,927 Lenhardt Apr. 5, 1927 2,126,476 Koonz Aug. 9, 1938 2,201,654 Schoen May 21, 1940 

